Prediction of bed fluctuation and expansion ratios for homogeneous ternary mixtures of spherical glass bead particles in a three‐phase fluidised bed

Abstract

AbstractThe prediction of the fluctuation and expansion ratios in three‐phase fluidised beds of homogeneous particles is of prime importance in designing the equipments and evaluating the efficiency of a number of physical and/or chemical operations of industrial importance. A clear knowledge of the hydrodynamic behaviour in a three‐phase fluidised bed is a prerequisite for this purpose. To explore this, a series of experiments have been carried out for homogeneous well‐mixed ternary mixtures of three different sizes of glass beads of varying compositions in a three‐phase fluidised bed. The hydrodynamic characteristics determined include the bed fluctuation and expansion ratios. The dependence of these quantities on the average particle diameter, superficial gas velocity and initial static bed height has been discussed. Based on dimensional and statistical analyses, correlations have been developed with the system parameters, viz., average particle diameter, initial static bed height and superficial velocity of the fluidising medium. Experimental values of bed fluctuation and expansion ratios have been found to agree well with those calculated from developed correlations.